ym4r_gm plugin marker_group question

I am using the ym4r_gm plugin with rails, and I am trying to use the
marker group feature. The main functionality I am trying to develop is
summed up by the following point from the ym4r_gm documentation.

Marker groups can be used for:
+ Keeping an index of markers, for example, in order to show one of
these markers in reponse to a click on a link (the way Google Local
does with the results of the search).

My initial page load, which plots the first set of markers on the map
works fine with the marker group. However, when I update the map via
ajax, the new markers are re-plotted, but it seems the marker_group is
lost, as I can no longer click on the links to show the marker on the

Does anyone have an idea of why I am loosing the ability to click on
my link to show the marker pop-up on the map?

Below is the code I am using:

#first controller function that is called
  def initialize_map
    @map = GMap.new("map_div")
    @map.control_init(:large_map => true,:map_type => true)
    @map.interface_init({ :dragging => true, :info_window=>
true, :double_click_zoom => true, :scroll_wheel_zoom => true })

def plot_points_on_map(@points)
   @markers = Hash.new
    for point in @points
      marker = GMarker.new(point.address, :title =>
"geocoded", :info_window => point.name, :icon => :icon_point)
      @markers[point.id] = marker
    @marker_group = GMarkerGroup.new(true, @markers)
    @map.overlay_global_init(@marker_group, "markerGroup")

Then in my partial _results.rhtml I have the following anchor
<% for point in @points %>
  <a href="#" onclick="markerGroup.showMarker(<%= point.id %>);return
false;">View on map</a>
<% end -%>

I have a form with various controls, that call the following when
submitted via ajax

def update_points_using_criteria
      @points = find_points
      @map = Variable.new("map")

And the corresponding rjs file

page << @map.clear_overlays
@markers.each_pair {|point_id, marker|
  page << @map.add_overlay(marker)
page.replace_html 'results-wide', :partial => 'results'